Related Experiment Videos
Lactococcus lactis uses MscL as its principal mechanosensitive channel
Joost H A Folgering1, Paul C Moe, Gea K Schuurman-Wolters
1Department of Biochemistry, Groninger Biomolecular Sciences and Biotechnology Institute and Material Science Centreplus, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
The Journal of Biological Chemistry
|December 23, 2004
Summary
Lactococcus lactis primarily uses the MscL channel for mechanosensitive solute release. This MscL channel is crucial for cell survival during osmotic downshifts, protecting against excessive solute loss.
Area of Science:
- Microbiology
- Molecular Biology
- Biophysics
Background:
- Mechanosensitive channels are vital for cellular homeostasis in response to osmotic stress.
- Lactococcus lactis possesses genes encoding potential mechanosensitive channels, including mscL and yncB.
Purpose of the Study:
- To elucidate the specific functions of mechanosensitive channels in Lactococcus lactis.
- To determine the role of the MscL channel in cellular response to osmotic downshifts.
Main Methods:
- Biochemical, physiological, and electrophysiological techniques were employed.
- Patch-clamp electrophysiology was used to characterize channel activity.
- Gene expression and disruption studies in Lactococcus lactis and Escherichia coli were performed.
- Osmotic downshift assays were conducted to assess cell survival and solute retention.
Main Results:
- Patch-clamp studies identified yncB and mscL as encoding MscS and MscL-like channels, respectively.
- Wild-type Lactococcus lactis membranes predominantly exhibited MscL channel activity.
- An mscL disruption mutant showed no mechanosensitive channel activity and impaired survival during osmotic downshifts.
- The mscL mutant retained more internalized glycine betaine but had significantly reduced survival rates.
Conclusions:
- Lactococcus lactis primarily utilizes the MscL channel for mechanosensitive solute release.
- The MscL channel plays a critical role in protecting Lactococcus lactis cells from osmotic downshock by regulating solute efflux.